Photoluminescence properties of ultrathin CsPbCl_3 nanowires on mica substrate

Fabricating high-quality cesium lead chloride(CsPbCl_3) perovskite nanowires(NWs) with dimension below 10 nm is not only of interests in fundamental physics, but also holds the great promise for optoelectronic applications. Herein, ultrathin CsPbCl_3 NWs with height of ～7 nm, have been achieved via vapor phase deposition method. Power and temperature-dependent photoluminescence(PL) spectroscopy is performed to explore the emission properties of the CsPbCl_3 NWs. Strong free exciton recombination is observed at ～3.02 eV as the temperature(T) is 78-294 K with binding energy of ～ 37.5 meV. With the decreasing of T, the PL peaks exhibit a first blueshift by 2 meV for T ～ 294-190 K and then a redshift by 4 meV for T ～ 190-78 K. The exciton–optical phonon interaction plays a major role in the linewidth broadening of the PL spectra with average optical phonon energy of ～48.0 meV and the interaction coefficient of 203.9 meV. These findings advance the fabrication of low dimensional CsPbCl_3 perovskite and provide insights into the photophysics of the CsPbCl_3 perovskite.

The Chinese herbal formula Tongluo Jiunao promotes expression of brain-derived neurotrophic factor/tropomyosin-related kinase B pathways in a rat model of ischemic brain injury

The neurotrophin-Trk receptor pathway is an intrinsic pathway to relieve damage to the central nervous system. The present study observed the effects of Tongluo Jiunao （TLJN）, which comprises Panax Notoginseng and Gardenia Jasminoides, on expression of brain-derived neurotrophic factor （BDNF） and tropomyosin-related kinase B （TrkB） in a rat model of focal cerebral ischemic injury. Xue Sai Tong （XST）, comprising Panax Notoginseng, served as the positive control. Mechanisms of neuroprotection were analyzed following TLJN injection. Following establishment of the middle cerebral artery occlusion models, TLJN and XST were intraperitoneally injected, and 2, 3 5-triphenyltetrazolium chloride staining results revealed that TLJN injection reduced infarct volume, suggesting that TLJN exerted a neuroprotective effect. Enzyme-linked immunosorbent assay results showed that TLJN elevated BDNF and growth associated protein-43 expression in ischemic brain tissues, as well as serum BDNF levels. Reverse-transcription polymerase chain reaction and western blot results showed that TLJN injection did not affect TrkB expression in the ischemic brain tissues of rats. These results suggested that TLJN injection reduced damage to ischemic brain tissues and increased BDNF expression. In addition, TLJN injection resulted in better promoting effects on neurotrophic factor expression compared with XST.

Single-cell profiling reveals a potent role of quercetin in promoting hair regeneration

Hair loss affects millions of people at some time in their life,and safe and efficient treatments for hair loss are a significant unmet medical need.We report that topical delivery of quercetin(Que)stimulates resting hair follicles to grow with rapid follicular keratinocyte proliferation and replenishes perifollicular microvasculature in mice.We construct dynamic single-cell transcriptome landscape over the course of hair regrowth and find that Que treatment stimulates the differentiation trajectory in the hair follicles and induces an angiogenic signature in dermal endothelial cells by activating HIF-1αin endothelial cells.Skin administration of a HIF-1αagonist partially recapitulates the pro-angiogenesis and hair-growing effects of Que.Together,these findings provide a molecular understanding for the efficacy of Que in hair regrowth,which underscores the translational potential of targeting the hair follicle niche as a strategy for regenerative medicine,and suggest a route of pharmacological intervention that may promote hair regrowth.

Strong exciton-photon interaction and lasing of two-dimensional transition metal dichalcogenide semiconductors

Two-dimensional(2D)transition metal dichalcogenide(TMDC)semiconductors not only hold great promises for the development of ultra-thin optoelectronic devices with low-energy consumption,but also provide ideal platforms to explore and tailor light-matter interaction,e.g.,the exciton-photon interaction,at the atomic level,due to their atomic thickness,large exciton binding energy,and unique valley properties.In recent years,the exciton-photon interactions in TMDC semiconductor microcavities,including the strong exciton-photon coupling and lasing,have drawn increasing attention,which may open up new application prospects for transparent,on-chip coherent,and quantum light sources.Herein,we review the research progresses of strong exciton-photon interaction and lasing of TMDC semiconductors.First,we introduce the electronic structure,exciton,and emission properties of semiconducting TMDCs in the weak exciton-photon coupling regime.Next,the progresses on strong exciton-photon interaction and exciton-polaritons of these TMDCs are discussed from the aspects of photophysics,materials and fabrications,spectroscopies,and controls.Further,the progresses on TMDC lasers are introduced in the aspects of cavity types and materials,and finally,the challenges and prospects for these fields are discussed.

Space-confined growth of monolayer ReSe2 under a graphene layer on Au foils

Vertical heterostructures based on two-dimensional(2D)materials have attracted widespread interest for their numerous applications in electronic and optoelectronic devices.Herein,we report the direct construct!on of an abnormal graphene/ReSe2 stack on Au foils by a two-step chemical vapor deposition(CVD)strategy.During the second growth stage,mono layer ReSe2 is found to prefere ntially evolve at the irUerface between the first-grown graphene layer and the Au substrate.The unusual stacking behavior is unraveled by in-situ"cutting open"the upper graphene from the defects to expose the lower ReSe2 using scanning tunneling microscopy(STM).From combination of these results with density functional theory calculations,the domain boundaries and edge sites of graphene are proposed to be adsorption sites for Re and Se precursors,further facilitating the growth of ReSe2 at the van der Waals gap of graphene/Au.This work hereby offers an intriguing strategy for obtaining vertical 2D heterostructures featured with an ultra-clean interface and a designed stacking geometry.

Analysis of photoluminescence behavior of high-quality single-layer MoS2

The ability to tailor and enhance photoluminescence (PL) behavior in two-dimensional (2D) transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS2) is significant for pursuing optoelectronic applications.To achieve this,it has been essential to obtain high-quality single-layer MoS2 and fully explore its intrinsic PL performance.Here,we fabricate single-layer MoS2 by a thermal vapor sulfurization method in which a pre-deposited molybdenum trioxide (MoO3) thin film is sulfurized over a short period (for several minutes) to turn into MoS2.These as-grown MoS2 crystals show quite strong PL,which is about one order of magnitude higher than that of chemical-vapor-deposited MoS2.Temperature- and power-dependent spectroscopy measurements disclose the apparent influence of sulfur (S) vacancies on the PL behavior and the noticeable free-to-bound exciton recombinations in the luminescence process.The fact that PL intensity of the sample in vacuum sharply lowered down relative to in air reveals that the high PL is facilitated by molecular adsorption on S vacancies in air.And multi-channel decay processes coupled with S vacancies are revealed in the time-resolved PL spectroscopy.In our work,single-layer MoS2 with high PL is synthesized and its defect-induced PL features are analyzed,which is of great importance for developing advanced nano-electronics and optoelectronics based on 2D structures.

China Nutrition and Health Surveys(1982−2017)

The status of nutrition and health among residents is one of the important indicators reflecting the developing level in a country or a region.China’s government initiated the first China National Nutrition Survey in 1959.The Second National Nutrition Survey and the Third National Nutrition Survey were then conducted in 1982 and 1992,respectively(1-2).The China National Nutrition and Health Survey(2002)combined the nutrition and chronic diseases survey and became the fourth survey(3).

Salt-assisted growth and ultrafast photocarrier dynamics of large-sized monolayer ReSe2

Owing to its anisotropic optical and electrical properties,rhenium diselenide(ReSe2)has garnered considerable attention recently as a candidate material for polarization-sensitive photodetectors.However,the direct and controllable synthesis of large-sized ReSe2 with a uniform thickness is still a great challenge.Herein,we have refined the synthesis method to obtain uniform monolayer ReSe2 flakes with a size of up to^106μm on sapphire via an ambient-pressure chemical vapor deposition technique using Na promoter from sodium chloride.Interestingly,optical pump-probe spectroscopy revealed a fast switching from saturable absorption(SA)to absorption enhancement(AE)in subpicosecond time scale,followed by a slower decay induced by exciton recombination.Furthermore,both AE and SA signals exhibited clear angular dependence with a periodicity of 180°,which reflected the dichroism in nonlinear absorption dynamics.In addition,the photocarrier dynamics including free-carrier transport and subpicosecond relaxation due to exciton formation or surface trapping was probed using time resolved terahertz spectroscopy.We believe that our study serves as a reference for atomically controlled synthesis of large-sized ReSe2 and provides useful insights on its optoelectronic properties for novel device applications.

Cooking Oil and Salt Intakes Among Children Aged 6−17 Years——China,2016−2017

Summary What is already known on this topic?High-level intakes of both cooking oil and salt are issues of concern in China as they can lead to an increased risk of chronic diseases later in life.Reducing intakes of cooking oil and salt should be prioritized in children.What is added by this report?Among children aged 6-17 years in China in 2016-2017,the median intake of cooking oil and salt were 27.7 and 6.1 g/d,respectively.The percentages of children with intake of cooking oil and salt that exceeded the recommended guidelines were 50.4%and 67.8%,respectively.

Serum Vitamin A Nutritional Status of Children and Adolescents Aged 6−17 Years—China,2016−2017

Summary What is already known on this topic?Vitamin A deficiency(VAD)in children is still a global public health problem,which needs continuous monitoring and timely intervention.What is added by this report?Using surveillance data from China Nutrition and Health Surveillance of Children and Lactating Mothers in 2016−2017,the prevalence of VAD and marginal deficiency was 0.96%and 14.71%,respectively.

A small molecule inhibitor targeting SHP2 mutations for the lung carcinoma

The RAS/mitogen-activated protein kinase(MAPK)pathway disorder induced by the missense mutations in the tyrosine-protein phosphatase non-receptor type 11(PTPN11)gene which resulted in the nonreceptor protein tyrosine phosphatase SHP2 dysfunction has been reported in many lung cancer cases.Moreover,the Src homology region 2(SH2)-containing protein tyrosine phosphatase 2(SHP2)mutation or deletion triggers multiple signaling pathway dysfunctions including RAS/MAPK,RAS/extracellular-signal-regulated kinase(ERK),phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT),Janus kinase/signal transducers and activators of transcription(JAK/STAT)and Hippo/yes-associated protein(YAP)which affect the expression of growth factors,cytokines and hormones.In recent years,the developing of the small molecule SHP2 inhibitors received a lot of attention.In this review,we summarize the recent years'progresses of the SHP2 inhibitors development for the lung cancer treatment.

Intake of Vitamin A,Thiamine,Riboflavin,Vitamin C,and Niacin Among Children Aged 6−11 Years Old—China,2016−2017

Summary What is already known on this topic?Insufficient intake of vitamins is one of the major nutritional problems in children aged 6-11 years old in China,and the problem is particularly severe for rural populations.What is added by this report?Among children aged 6-11 years old in 2016-2017,the average intakes of vitamin A,thiamine.

Weight Status and Self-Perception of Weight Among Women of Childbearing Age—China,2015

Summary What is already known about this topic?Both lean and obese women carry a risk for adverse pregnancy outcomes.Correct self-perception of body weight status is necessary for optimal weight control.What is added by this report?Data from the Nutrition and Chronic Disease Surveillance of Chinese Residents in 2015 were used in this study.The weight status and self-perception of weight among women of childbearing age in China were analyzed to provide basic data for improving the nutritional health of women of childbearing age.

Recent research and development of DYRK1A inhibitors

Dual specificity tyrosine phosphorylation regulated kinase 1 A(DYRK1 A) is an evolutionarily conserved protein kinase belonging to the CMGC kinase family, which is closely related to Down syndrome(DS)and Alzheimer’s disease(AD). In recent years, not only the treatment of diabetes, but also the treatment of cancer gradually focuses on targeting DYRK1 A. Therefore, a series of DYRK1 A inhibitors have been developed to treat relevant diseases and clarify their treatment mechanism furtherly. DYRK1 A inhibitors are mainly divided into natural products and synthetic compounds. Among them, harmine is an excellent DYRK1 A inhibitor. Therefore, the synthetic DYRK1 A inhibitors are mainly based on harmine, which greatly enriches the structure and quantity of DYRK1 A inhibitors. The interaction between the inhibitors and the DYRK1 A protein has a guiding significance in predicting the activity of the inhibitors, and plays an irreplaceable role in the design of the compounds. This paper mainly reviews DYRK1 A inhibitors found in recent years and their structure-activity relationship, looking forward to providing a theoretical basis for the development of DYRK1 A inhibitors.

Consumption of Milk and Dairy Products Among Junior High and Senior High School Students — China, 2016–2017

Summary What is already known about this topic?Chinese dietary guidelines recommend an intake of milk and dairy products to be closely related to human health.Although the production capacity of dairy in China is strong,the per capita consumption of dairy products is not high.What is added by this report?This report showed that the consumption rate of milk and dairy products of junior high and senior high school students in China was 82.5%from 2016 to 2017.Only 44.1%of them consumed milk and dairy products every day.Only 20.4%of these students reached intake levels recommended by the Dietary guidelines for Chinese residents(2016).What are the implications for public health practice?Milk and dairy products are a key food group in a healthy dietary pattern.To cultivate a healthy eating habit of including dairy for children and adolescents,the government,suppliers,schools,and parents need to cooperate together.

Energy and Macronutrient Intake Among Children Aged 6−11 Years Old—China,2016−2017

Summary What is already known on this topic?Low level energy and macronutrient intakes and dietary imbalances are still important issues and should be prioritized in children aged 6-11 years old in China.What is added by this report?Among children aged 6-11 years in China in 2016-2017,the average protein intake was 55.2 g/d in urban areas and was higher than the estimated 45.4 g/d in rural areas.

Beverage Consumption of Children and Adolescents Aged 6−17 Years—China,2016−2017

Summary What is already known on this topic?Beverage consumption has become a problematic dietary behavior in children and adolescents.Excessive drinking of beverages,especially sugary beverages,can increase the risk of chronic diseases such as obesity,dental cavities,and diabetes.What is added by this report?This report revealed the beverage consumption rate was higher in males,in urban areas.